Red Algae (Division Rhodophyta)
Red Algae of this phylum are also characteristically marine. Rhodophyta are cosmopolitan, found from the arctic to the tropics. 98% are marine. A number of species is unicellular, but most species are multicellular.
Red algae exhibit considerable variety of form and coloration. Red algae are not always red, many are as dark a color as black. Pigments include chlorophyll A and chlorophyll D, xanthophyll, carotene, phycocyanin, and phycoerythrin.
They are important members of coral reefs. They can include in their cell walls calcium carbonate which makes the plants hard and resistant to wear.
Red algae are red because of the presence of the pigment phycoerythrin; this pigment reflects red light and absorbs blue light. Because blue light penetrates water to a greater depth than light of longer wavelengths, these pigments allow red algae to photosynthesize and live at somewhat greater depths than most other “algae”.
A few forms inhabit fresh water. Freshwater red algae are largely restricted to streams and rivers, but also can occur in other inland habitats, such as lakes, hot springs, soils and caves.
End of Red AlgaeMore about Algae…
Significance of Algae